This invention relates to resonant optical microcavities and to switching optical signals.
The prior art contemplates switching optical signals by controlling the index of refraction of the optical medium in which signal propagates. The disadvantage of these devices is the strong pump power required for total switching. This high pumping power limits the use of these switches in integrated circuits for example where non-local optical power source is used.
The present invention provides an all-optical switch including a microcavity structure that is resonant with both an optical pumping source and an input optical signal. The microcavity structure includes a cavity in between two reflectors. The transmission of the input optical signal through the structure is switched from one to zero, by varying the pump intensity incident on the structure. The microcavity structure provides amplification of the pumping energy allowing for nonlocal optical power source.
In accordance with one exemplary embodiment of the invention there is provided an optical switch for controllably switching an input optical signal using an optical pumping source. The switch includes a resonant microcavity structure with a resonance tunable by the optical pumping source including a cavity in between first and second reflectors. The resonant microcavity structure has a high penetration length at the wavelength of the optical pumping source and at the wavelength of the input optical signal. The optical pumping source and the input optical signal are at resonance or multiple resonance of the microcavity structure. The swiching time can be very short (depending on the specific of the structure and material used) therefore the structure also provides a way for fast optical modulation using a continuous wave pumping.